1. Field of the Invention
This invention relates to a sheet feeding device and image forming apparatus, and in particular, relates to the sheet feeding device and image forming apparatus including a unit for raising sheets of paper to be fed through the use of a lift motor and other elements.
2. Description of Related Art
In conventional sheet feeding devices, a lifting unit such as a lift motor is generally used to raise sheets of paper to an optimal feeding position according to the quantity of paper.
A sheet feeding device that detects the residual quantity of paper by means of an elevation drive mechanism is disclosed in Japanese unexamined patent publication No. 06-144643, for example.
According to JP 06-144643, a marker detecting sensor senses a sheet residual quantity detecting marker provided on an elevating path to detect the residual quantity of paper. Consequently, the sheets of paper are moved up to the optimal position based on the quantity of paper.
However, according to JP 06-144643, when the residual quantity of paper to be fed is small, it takes some time to elevate the paper. It would be possible to decrease time by raising the paper at high speed, however, excessively high speed may cause the lift motor or other elements to overrun, thereby creating the possibility for the sheets of paper not to stop at the optimal feeding position.